638284672650240 has 2112 divisors, whose sum is σ = 3027707087827968. Its totient is φ = 124828463923200.

The previous prime is 638284672650221. The next prime is 638284672650241. The reversal of 638284672650240 is 42056276482836.

638284672650240 is a `hidden beast` number, since 6 + 3 + 8 + 2 + 8 + 4 + 67 + 26 + 502 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (2112).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (638284672650241) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1628409480 + ... + 1628801400.

Almost surely, 2^{638284672650240} is an apocalyptic number.

638284672650240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638284672650240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1513853543913984).

638284672650240 is an abundant number, since it is smaller than the sum of its proper divisors (2389422415177728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638284672650240 is a wasteful number, since it uses less digits than its factorization.

638284672650240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391996 (or 391966 counting only the distinct ones).

The product of its (nonzero) digits is 185794560, while the sum is 63.

The spelling of 638284672650240 in words is "six hundred thirty-eight trillion, two hundred eighty-four billion, six hundred seventy-two million, six hundred fifty thousand, two hundred forty".